The primary goals of this project are to determine the involvement of cytokines in relation to HIV-1 infection in the pathology of CNS disease, characterize the DNA sequences in the envelope gene of HIV in relation to CNS tropism, neuropsychiatric disease, and pathology, and to determine the effects of drugs abused in Miami on replication and LTR controlled expression of HIV. We reported that the reactive macrophage/monocyte is the cell predominantly infected in the brain and that cocaine accelerates HIV replication at physiological concentrations. We hypothesize that HIV- pathogenesis in brain is due to production of cytokines (TNF-alpha, Il-1, and Il-6) by infected macrophages, that specific DNA sequences of the HIV envelope protein are associated with infection of the CNS, neurological involvement such as encephalopathy, and cognitive motor disorder (AIDS dementia complex) in drug abusers, and that effects of drug-induced stimulation of HIV replication occur at the HIV LTR. We will attack the following specific alms: 1. We will isolate and culture macrophage/monocytes from AIDS brain tissue in order to confirm their infectivity by HIV and to isolate HIV from these cells. We will compare cells and viruses from drug abusers to other risk groups. We have a high success rate of isolation of HIV and cells from post-mortem brain tissue and over a period of 5 years we have studied 112 brains. We will also isolate cells from HIV-negative drug abusers. We hypothesize that brain cells from this group will be more susceptible to HIV due to drug-induced immune system damage. 2. We will determine the mechanisms of pathogenesis of HIV infection in the CNS: the association of cytokine gene expression with specific cells in areas of pathology. We have shown that cytokine production is part of local inflammation and pathogenesis in the brain and is associated with areas of pathology (multinucleate giant cells and microglial nodules). We will determine if brain tissue from drug abusers exhibits changes in neuropathology and immunohistochemical distribution of cytokines vis a vis HIV-associated pathogenesis. This is expected since cytokines are crucial communication molecules in the immune system which dysfunctions due to AIDS and drug-abuse. This work will answer the major question of pathogenesis by HIV: what factors in addition to HIV infection contribute to widespread pathogenesis in brain even though the infection itself appears to be more limited. 3. We will examine the heterogeneity of HIV by PCR, cloning, and DNA sequencing for drug abusers and other risk groups. We will also investigate HIV envelope sequences in a selection of neurologically well-characterized patients to address the issue of the specificity of the CNS (CSF) sequences in drug abusers in Miami. We have commenced DNA sequencing directly from brain tissue and as a result of the proposed work, we will decisively determine the "epidemiology" of specific HIV DNA sequences in the brain. 4. We will continue to determine the effects on HIV replication of drugs abused in Miami. Drug abuse and AIDS are increasing in Miami and world-wide and have reached epidemic proportions. This work will increase our understanding of the effects of drug abuse on HIV replication and pathogenesis of neurological disease in drug abusers, and will increase our knowledge of the sequence heterogeneity of CNS-tropic HIV-1 in order to facilitate vaccine production against these strains of HIV.